The invention relates to a measuring device of the useful load and of the load on the axles of a truck comprising a frame and a tipper, the measurement being effected by load cells mounted between said frame and said tipper.
According to the U.S. Pat. No. 3,927,724 an apparatus is known for holding a tipper on the frame of a vehicle and comprising an incorporated weighing device. The arrangement of the apparatus permits to prevent or to reduce the twisting constraints and the forces of elongation on the load cells utilized in the systems of weighing of vehicles. However, the device does not prevent the constraints of flexion in a plane perpendicular to the axis of the wheels of the vehicle, such constraints contributing to alter the measurement of the weight of the useful load.
The U.S. Pat. No. 3,279,550 describes a truck load measuring system in which load sensing devices are placed between the load bearing frame and the truck frame at each corner of the load bearing frame. The upper portion of the load sensing device is fixed to the load bearing frame and the lower portion to the truck frame. Both portions are connected together by welded plates which permit a limited flexion of the upper portion of the load sensing device. The load cell is mounted between an upper and a lower channel, in the middle of these channels. This permits to eliminate the effects of the lateral and shear forces on the load cell, these forces being transmitted to the truck frame by the welded plates. The only force acting on the load cell is in the direction of the axis of this cell. However, the system does not permit an axial displacement of the load bearing frame along the longitudinal axis of the truck nor the displacement along an axis perpendicular to the latter. The utilization of four load sensing devices does not either permit a rotation of the load bearing frame about the longitudinal axis of the truck.
It is therefore the object of the present invention to provide a precise measuring device of the useful load and of the load on the axles of a truck in which load cells are exclusively submitted to constraints resulting from the weight of the tipper and of the useful load supported by the tipper, independently from the place where the useful load is disposed in the tipper and, within certain limits, from the tilting of the truck with respect to a horizontal plane.